University of Adelaide researchers have designed a new molecule which targets a protein essential to the growth of most cancers. The protein target is called proliferating cell nuclear antigen (PCNA), also known as the human sliding clamp.

Dr. John Bruning, Senior Research Fellow at the University's Institute for Photonics and Advanced Sensing (IPAS) and project leader said, "PCNA is required for DNA replication and is therefore essential for rapidly dividing cancer cells. PCNA holds the machinery that copies DNA. The DNA slides through the center of this donut-shaped protein where it is replicated.”

"If we can inhibit the action of this protein, the cells can't make DNA, so they can't divide. This is really tackling cancer at ground zero.”

The molecule designed by the multi-disciplinary team at IPAS interacts with PCNA, presenting a promising breakthrough strategy for an anti-cancer treatment that inhibits PCNA.

"In this study, we have taken a protein fragment that naturally interacts with PCNA and transformed it using smart chemistry into a drug-like molecule," says lead author Dr. Kate Wegener, Ramsay Postdoctoral Research Fellow in the University of Adelaide's School of Biological Sciences.

"We've changed its chemistry to protect it from degrading like the natural protein, and so that it works better." Hence, it shows higher effectiveness over other PCNA inhibitors and is less likely to produce side-effects.

"This is a first. It's the first in this type of inhibitor and it will pave the way for a new class of drugs inhibiting the proliferation of cancerous cells," says Dr. Bruning.